White Plains is filled with history.  In 1758, White Plains became the seat of Westchester County when the colonial government for the county left West Chester, which was located in what is now the northern part of the borough of the Bronx, in New York City. The unincorporated village remained part of the Town of Rye until 1788, when the Town of White Plains was created. 

On July 9, 1776, a copy of the Declaration of Independence was delivered to the New York Provincial Congress, which was meeting in the county courthouse. The delegates quickly adopted a resolution approving the Declaration, thus declaring both the colony's independence and the formation of the State of New York. The Declaration itself was first publicly read from the steps of the courthouse on July 11. 

During September and October 1776, troops led by George Washington took up positions in the hills of the village, hotly pursued by the British under General Sir William Howe, who attacked on October 28. The Battle of White Plains took place primarily on Chatterton Hill, (later known as "Battle Hill," and located just west of what was then a swamp but is now the downtown area) and the Bronx River. The Battle of White Plains  ended in defeat for General George Washington and his army as they retreated from New York City following a series of British victories earlier that summer. Washington attempted to make a stand on a stretch of high ground to allow for the orderly consolidation and evacuation of personnel and much needed supplies. British forces under General Lord William Howe failed to trap the Continental Army on Manhattan but were still able to envelop this position on a critical piece of terrain and force Washington’s army to retreat. The loss at White Plains and the successful British capture of Forts Washington and Lee on the Hudson River demonstrated the continuing tactical limits of Washington and the Continental Army. In the aftermath, Washington dispersed his army throughout the Hudson Highlands and New Jersey to avoid further calamity.